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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#include "common/endian.h"
#include "sci/sci.h"
#include "sci/exereader.h"
namespace Sci {
int _bitCount;
uint16 _bits;
Common::Platform getGameExePlatform(Common::SeekableReadStream *exeStream) {
byte magic[4];
// Make sure that the executable is at least 4KB big
if (exeStream->size() < 4096)
return Common::kPlatformUnknown;
// Read exe header
exeStream->read(magic, 4);
// Check if the header contains known magic bytes
// Information obtained from http://magicdb.org/magic.db
// Check if it's a DOS executable
if (magic[0] == 'M' && magic[1] == 'Z') {
return Common::kPlatformPC;
}
// Check if it's an Amiga executable
if ((magic[2] == 0x03 && magic[3] == 0xF3) ||
(magic[0] == 0x7F && magic[1] == 'E' && magic[2] == 'L' && magic[3] == 'F')) {
return Common::kPlatformAmiga;
}
// Check if it's an Atari executable
if ((magic[0] == 0x60 && magic[1] == 0x1A))
return Common::kPlatformAtariST;
// Check if it's a Mac exe
// Resource map offset
int32 offset = (int32)READ_BE_UINT32(magic);
offset += 28;
if (exeStream->size() <= offset)
return Common::kPlatformUnknown;
// Skip number of types in map
exeStream->skip(2);
// uint16 val = exeStream->readUint16BE() + 1;
exeStream->skip(2);
// Keep reading till we find the "CODE" bit
while (!exeStream->eos()) {
exeStream->skip(4);
if (exeStream->eos())
return Common::kPlatformUnknown;
exeStream->read(magic, 4);
if (exeStream->eos())
return Common::kPlatformUnknown;
if (!memcmp(magic, "CODE", 4)) {
return Common::kPlatformMacintosh;
}
// Skip to the next list entry
exeStream->skip(4);
if (exeStream->eos())
return Common::kPlatformUnknown;
}
// If we've reached here, the file type is unknown
return Common::kPlatformUnknown;
}
bool isLZEXECompressed(Common::SeekableReadStream *exeStream) {
uint32 filepos = 0;
exeStream->seek(0, SEEK_SET);
// First 2 bytes should be "MZ" (0x5A4D)
if (exeStream->readUint16LE() != 0x5A4D) // at pos 0, +2
return false;
exeStream->skip(6);
// Header size should be 2
filepos = exeStream->readUint16LE();
if (filepos != 2) // at pos 8, +2
return false;
exeStream->skip(12);
// Calculate code segment offset in exe file
filepos += exeStream->readUint16LE(); // at pos 22, +2
filepos <<= 4;
// First relocation item offset should be 0x1c
if (exeStream->readUint16LE() != 0x1c) // at pos 24, +2
return false;
// Number of overlays should be 0
if (exeStream->readUint16LE() != 0) // at pos 26, +2
return false;
// Look for LZEXE signature
byte magic[4];
exeStream->read(magic, 4);
if (memcmp(magic, "LZ09", 4) && memcmp(magic, "LZ91", 4))
return false;
// Seek to offset 8 of info table at start of code segment
exeStream->seek(filepos + 8, SEEK_SET);
if (exeStream->err())
return false;
// Read size of compressed data in paragraphs
uint16 size = exeStream->readUint16LE();
// Move file pointer to start of compressed data
filepos -= size << 4;
exeStream->seek(filepos, SEEK_SET);
if (exeStream->err())
return false;
// All conditions met, this is an LZEXE packed file
// We are currently at the start of the compressed file data
return true;
}
uint getBit(Common::SeekableReadStream *input) {
uint bit = _bits & 1;
_bitCount--;
if (_bitCount <= 0) {
_bits = input->readByte();
_bits |= input->readByte() << 8;
if (_bitCount == -1) { // special case for first bit word
bit = _bits & 1;
_bits >>= 1;
}
_bitCount += 16;
} else
_bits >>= 1;
return bit;
}
Common::String readSciVersionFromExe(Common::SeekableReadStream *exeStream, Common::Platform platform) {
int len = exeStream->size();
unsigned char *buffer = NULL;
// Read the executable
bool isLZEXE = isLZEXECompressed(exeStream);
if (!isLZEXE) {
buffer = new unsigned char[exeStream->size()];
exeStream->seek(0, SEEK_SET);
exeStream->read(buffer, exeStream->size());
} else {
buffer = new unsigned char[exeStream->size() * 3];
_bitCount = 0;
// Skip LZEXE header
exeStream->seek(32, SEEK_SET);
int pos = 0;
int repeat;
short offset;
while (1) {
if (exeStream->ioFailed()) {
warning("Error reading from input file");
delete[] buffer;
return NULL;
}
if (getBit(exeStream)) {
buffer[pos++] = exeStream->readByte();
} else {
if (getBit(exeStream)) {
byte tmp[2];
exeStream->read(tmp, 2);
repeat = (tmp[1] & 0x07);
offset = ((tmp[1] & ~0x07) << 5) | tmp[0] | 0xE000;
if (repeat == 0) {
repeat = exeStream->readByte();
if (repeat == 0) {
len = pos;
break;
}
else if (repeat == 1)
continue;
else
repeat++;
} else
repeat += 2;
} else {
repeat = getBit(exeStream) << 1;
repeat += getBit(exeStream) + 2;
offset = exeStream->readByte() | 0xFF00;
}
while (repeat > 0) {
buffer[pos] = buffer[pos + offset];
pos++;
repeat--;
}
}
}
}
// Find SCI version number
int state = 0;
/* 'state' encodes how far we have matched the version pattern
** "n.nnn.nnn"
**
** n.nnn.nnn
** 0123456789
**
** Since we cannot be certain that the pattern does not begin with an
** alphanumeric character, some states are ambiguous.
** The pattern is expected to be terminated with a non-alphanumeric
** character.
*/
int accept;
unsigned char *buf = buffer;
// String-encoded result, copied from buffer
char currentString[10];
Common::String resultString;
for (int i = 0; i < len; i++) {
unsigned char ch = *buf++;
// By default, we don't like this character
accept = 0;
if (isalnum(ch)) {
accept = (state != 1 && state != 5 && state != 9);
} else if (ch == '.') {
accept = (state == 1 || state == 5);
} else if (state == 9) {
// Terminate string
currentString[9] = 0;
// Return the current string if it's parseable
SciVersion version;
if (getSciVersionFromString(currentString, &version, platform)) {
delete[] buffer;
return currentString;
}
// Save the found string and continue searching
resultString = currentString;
}
if (accept)
currentString[state++] = ch;
else
state = 0;
}
delete[] buffer;
return resultString;
}
bool getSciVersionFromString(Common::String versionString, SciVersion *version, Common::Platform platform) {
*version = SCI_VERSION_AUTODETECT;
if (platform == Common::kPlatformAmiga) {
if (versionString.hasPrefix("1.002.")) {
*version = SCI_VERSION_0;
} else if (versionString.hasPrefix("1.003.")) {
*version = SCI_VERSION_01;
} else if (versionString.hasPrefix("1.004.")) {
*version = SCI_VERSION_01;
} else if (versionString.hasPrefix("1.005.")) {
*version = SCI_VERSION_1;
} else if (versionString == "x.yyy.zzz") {
// How to map it?
} else {
return false;
}
} else if (versionString.hasPrefix("S.old.")) {
*version = SCI_VERSION_01;
} else if (versionString.hasPrefix("1.ECO.")
|| versionString.hasPrefix("1.SQ1.")
|| versionString.hasPrefix("1.SQ4.")
|| versionString.hasPrefix("1.LS5.")
|| versionString.hasPrefix("1.pq3.")
|| versionString.hasPrefix("FAIRY.")
|| versionString.hasPrefix("T.A00.")) {
*version = SCI_VERSION_1;
} else if (versionString.hasPrefix("L.rry.")
|| versionString.hasPrefix("l.cfs.")) {
*version = SCI_VERSION_1_1;
} else if (versionString == "x.yyy.zzz") {
// How to map it?
} else {
// Unknown or not a version number
return false;
}
return true;
}
} // End of namespace Sci
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